Python：排列组合三个函数permutations,combinations,product

from itertools import permutations,combinations,producta = [1,2,3,4]
b = [5,6,7,8]A = permutations(a,3)
print(list(A))B = combinations(a,3)
print(list(B))C = product(a,b)
print(list(C))

permutations(a,3)是排列

combinations(a,3)是组合

product(a,b)是两个集合元素的互组合